interdisciplinary research towards sustainability

International Journal of Sustainable Development & World Ecology 15 (2008) 284–287 DOI 10.3843/SusDev.15.4:1

Coping with an urbanising world: interdisciplinary research towards sustainability Jingzhu Zhao1, Yong-Guan Zhu1, Guofan Shao2 and David Ness3 1

Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China Department of Forestry and Natural Resources, Purdue University, West Lafayette, USA 3 Institute for Sustainable Systems and Technologies, University of South Australia, Adelaide, Australia 2

Urban environmental research should promote sustainability of the urban environment and develop harmonious urban systems through partnerships with urban planners and policymakers. Contrary to the intensity of urban or urbanisation studies, there have been a relatively small number of urban environmental studies that have explicitly connected ‘urbanisation’ with ‘environment’. The Forum was intended to promote integrated studies on the urban environment by providing a communication platform to interested scholars on urban environment around the world.

In response to the great challenges of rapid urbanisation and increases in the need to build ‘harmonious’ cities, i.e. cities with a high quality of life, the Chinese Academy of Sciences, in collaboration with the International Journal of Sustainable Development and World Ecology, has taken the lead by organising the 1st Xiamen International Forum on Urban Environment, held in Xiamen, China, between November 28 and 29, 2007. The forum attracted almost 100 participants from around the world. This introductory paper summarises the key topics presented in this special issue and associated supplement on urban sustainability and environmental management. Urbanisation is generally considered as a positive process of societal development; however, rapid urbanisation is also one of the challenges facing the world in the twenty-first century. The twentieth century witnessed the most rapid urbanisation in human history, and by 2007, more than half of the people on Earth lived in cities. However, urbanisation has negative impacts, particularly as a cause of environmental pollution derived by intensive energy consumption and material flows (‘material metabolism’), and leading to dramatic changes in land use, loss of biodiversity, habitat fragmentation and a decline in ecosystem services. Therefore, studies on urbanisation and its environmental consequences have become urgent and are a focal topic for the scientific community worldwide.

URBAN ENVIRONMENTAL MANAGEMENT The study of urban environmental management involves assessment of urban systems and linkages to policymaking processes. The paper by Ness addressed urban infrastructure and resource productivity (a term related to eco-efficiency) (Ness 2008), with particular reference to the development of a ‘circular’ economy in China, i.e. with efficient recycling of materials. He considered the contribution of transport, energy, water and the built infrastructure to resource consumption, greenhouse gas emissions and the ecological footprint and ways in which China can move towards a Factor 10 improvement in resource productivity. Zhao and colleagues took a wider view and looked

Correspondence: Jingzhu Zhao, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361003, China. Email: [email protected]

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at sustainable development in the Asia-Pacific region (Zhao et al. 2008). They considered the importance of holistic, integrated or ‘systems’ thinking, and its potential to achieve synergies. They proposed the integration or coupling of urban development and the ecol-environment process for sustainable cities, suggesting a policy framework on sustainable consumption and production that emphasises Green Growth. Several papers addressed the impact of urbanisation on the natural environment, landscape and ecology. The influence of forests on the carbon budget and on the urban landscape was considered in two papers, both of which emphasised the importance of reforestation to mitigate CO2 increases. Shao and collaborators summarized general effects of urbanisation on carbon sequestration and used remote sensing data to demonstrate land-use changes in north-central Indiana, showing that the region has become an increasing source of CO2 in the past half-century because of urbanisationdominated land-use change (Shao et al. 2008). Deng and co-workers considered the ecosystem services provided by forests and urban forest landscape spatial patterns, ecological effects, economic assessment, and ecological and economic benefits (Deng et al. 2008). Effects of urbanisation on marine and freshwater systems were considered in several papers. Valuation of large-scale ecosystem services was covered by Wang and colleagues, focusing on the Yangtze River delta and its role in mitigating floods and droughts, water purification and supply, and the detoxification and decomposition of wastes (Wang et al. 2008). The effects of urban development around the Bohai Sea on the surrounding coastal and marine ecosystems were considered by Qiu and colleagues (Qiu et al. 2008). Huang and co-workers noted the importance of marine protected areas and presented a system to help identify relative ecological security in order to prioritise actions and assess the ecological implications of management and policy decisions (Huang et al. 2008). Finally, Yang and colleagues showed their modelling simulations to assess the hydrological impacts of runoff and non-point source pollutants from urban developments (Yang et al. 2008). Li described the use of sustainability assessment and indicators for mining communities, and suggested this work could be extended to wider sustainability assessments (Li et al. 2008). This

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paper complemented other speakers and discussion that emphasised the need to determine where to put efforts for best results, e.g. where most energy efficiencies and sustainable development can be achieved, and the need to track and monitor progress towards improvements. Finally, Duan and colleagues presented their model and indicator system, the Energy Consumption Unit Geometric Average (ECUGA) elasticity coefficient (Duan et al. 2008). They applied their simulations in developed and less developed countries and concluded that once urbanisation reached a certain level, the increased energy use of cities starts to decrease.

URBAN ENVIRONMENTAL PROCESSES Urban environmental processes can be generally considered as urban metabolism, which is clearly elaborated by the paper of plenary speaker, Manning, who focused on the role of trees in urban environmental quality (Manning 2008). Urban trees reduce runoff, reduce heat islands and provide shade but may increase levels of biogenic volatile organic compounds in urban air. Environmental problems during urbanisation are, in principle, driven by the intensity of energy consumption and material flows per unit land area and per capita. Water shortage and pollution are perhaps the most pressing issues in the urban environment. Field gave a comprehensive presentation on the use of membrane technology in water treatment and water reuse in urban settings. He also touched upon some of the key issues that limit the large application of membrane technology, such as critical/sustainable flux (Field 2008). Eutrophication of Lake Erhai following economic and population increases was addressed by Yan and colleagues (Yan et al. 2008). Both warning and management of flooding should include not only the quantity, but also the quality of the urban water system. Soil quality in urban area was also addressed in a paper by Miao and colleagues (Miao et al. 2008). Risk assessment is an issue related to contamination sources, exposure pathways and types of biological receptors. In the urban environment, both exposure pathways and biological receptors are different from other scenarios. Nevertheless, one of the key uncertainties remains the bioavailability of contaminants in the environmental matrices.

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Air quality in Beijing in relation to vehicle emissions was considered by Wu (Wu et al. 2008) based on cost analyses of the socio-economic–natural complex ecosystem. Urban landscape pattern changes in Beijing were examined by Ma et al. (2008) in terms of ecosystem health and urban planning. Ding and colleagues investigated the impact of economic development and greenhouse gas emissions, presenting guidelines towards achieving a low carbon economy and sustainable development (Ding et al. 2008). Social and economic cost and the health and ecological impact of environmental pollution have created demands for pollution control and environmental remediation. The paper by Yuan focused on some cutting-edge technologies in developing materials for environmental remediation and pollution control (Yuan 2008). Zhang and colleagues presented a method for anaerobic digestion of activated sludge (Zhang et al. 2008), while Liang and colleagues considered wastewater discharge from the pulp and paper industry (Liang et al. 2008). Environmental materials science should receive more attention in urban environmental research, and scientists should in the future divert some of their efforts from the laboratory to the field because, at the end of the day, we must convert these technologies into products that can be easily applied by various stakeholders. Papers on urban landscape ecology were given by Dai et al. and Lin et al., using data from industrial cities in northeast China and the coastal city of Xiamen, where the forum was held (Dai et al. 2008; Lin et al. 2008). Urban air quality was underrepresented in this issue. Liu gave a talk on modelling surface ozone in Beijing based on motor vehicle emissions (Liu et al. 2008). This work is an encouraging attempt to tackle a very complex issue, as ozone level has close links with urban vegetation dynamics and climate change.

Many other interesting presentations made at the symposium could not be included in this brief collection of papers. As it is, the papers have been split into two parts, issue 15.5 of the Journal and an accompanying supplement.

CONCLUSION AND RECOMMENDATIONS As the planet becomes more urbanised, it is urgent to integrate our knowledge and technologies in tackling the associated environmental problems. In addition, it is essential to ensure that results from environmental studies can be effectively implemented by urban policymakers, planners and developers. It is suggested that a high-level strategic analysis be undertaken to identify the most pressing urban environmental issues and where to put the efforts for best results. Subject to this exercise being undertaken, the following areas could be high among the priorities:

• Science-based urban planning and environmental management;

• Urban ecosystem health and management; • Urban biogeochemical processes and environmental quality;

• Development of integrative technologies for pollution control and environmental remediation; • Solid waste management and waste-to-resources technologies; • Holistic consideration of urban environmental systems and their connectivity; • Green Growth and resource productivity: enabling economic growth whilst reducing resource consumption and environmental degradation, including policy measures such as pricing and green taxes.

REFERENCES Dai L, Zhao X, He H, Deng H, Yu D, Zhou L and Wu S. Evaluating land-use suitability of an industrial city in northeast China. International Journal of Sustainable Development & World Ecology 2008;15:377–81 Deng H, Song M, Chen C and Rong B. Current situation and development of Chinese urban forestry.

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International Journal of Sustainable Development & World Ecology 2008;15:370–76 Ding D, Dai D and Zhao M. Development of a lowcarbon economy in China. International Journal of Sustainable Development & World Ecology 2008; 15:330–35



Duan J, Yan Y, Zheng B and Zhao J. Analysis of the relationship between urbanisation and energy consumption in China. International Journal of Sustainable Development & World Ecology 2008; 15:308–16 Field R.Water re-use: is there a place for membranes? International Journal of Sustainable Development & World Ecology 2008;15:S11–S17 Huang YF, Cui SH and Ouyang ZY. Integrated ecological assessment as the basis for management of a coastal urban protected area: A case study of Xiamen, China. International Journal of Sustainable Development & World Ecology 2008;15:388–93 Li ZX, Zhao YQ and Zhao HY. Assessment indicators and methods for developing the sustainability of mining communities. International Journal of Sustainable Development & World Ecology 2008;15: S35–S43 Liang J, He YL and Liu YH. Integrating water-use networks in a paper mill. International Journal of Sustainable Development & World Ecology 2008;15: S44–S50 Lin T, Xue XZ, Huang J and Cui SH. Assessing egrets’ ecological safety in the urban environment: a case study in Xiamen, China. International Journal of Sustainable Development & World Ecology 2008;15: 382–87 Liu F, Zhu Y and Zhao Y. Contribution of motor vehicle emissions to surface ozone in urban areas: A case study in Beijing. International Journal of Sustainable Development & World Ecology 2008;15: 344–48 Ma M, Lu Z and Sun Y. Population growth, urban sprawl, and landscape integrity of Beijing City. International Journal of Sustainable Development & World Ecology 2008;15:325–29 Miao C, Liu B, Gao Y and Zhang T. Evaluation of different procedures to interpolate particle-size distribution in black soils. International Journal of Sustainable Development & World Ecology 2008;15: S56–S62 Manning WJ. Plants in urban ecosystems: essential role of urban forests in urban metabolism and succession toward sustainability. International Journal of Sustainable Development & World Ecology 2008;15:361–69 Ness D. Sustainable urban infrastructure in China: Towards a Factor 10 improvement in resource

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productivity through integrated infrastructure systems. International Journal of Sustainable Development & World Ecology 2008;15:287–300 Qiu J, Gao Z and Zhao J. Ecosystem approach to management of the Bohai Sea Region: towards sustainable development of the coastal urban areas. International Journal of Sustainable Development & World Ecology 2008;15:S25–S34 Shao G, Qian TJ, Liu Y and Martin B. The role of urbanisation in increasing atmospheric CO2 concentrations: Think globally, act locally. International Journal of Sustainable Development & World Ecology 2008;15:301–307 Wang X, Wang S, Yan S, Zhang H and Shao T. Assessing the values of ecosystem services of the Yangtze Delta, China. International Journal of Sustainable Development & World Ecology 2008;15:S18–S24 Wu G, Sun Y, Jia J and Yan Y. Evaluating automobiles effects on the socio-economic-natural complex ecosystem in Beijing. International Journal of Sustainable Development & World Ecology 2008;15: 336–343 Yan C, Lu X and Zhao X. Protection and sustainable utilisation of water resources in Lake Erhai basin. International Journal of Sustainable Development & World Ecology 2008;15:356–60 Yang L, Ma KM, Guo QH and Bai X. Evaluating long-term hydrological impacts of regional urbanisation in Hanyang, China, using a GIS model and remote sensing. International Journal of Sustainable Development & World Ecology 2008; 15:349–55 Yuan G. Environmental materials research: Opportunities and challenges in China. International Journal of Sustainable Development & World Ecology 2008; 15:S1–S10 Zhang L, Yin J and Liu L. Mesophilic, two-phase anaerobic digestion of activated sludge pretreated with ultrasound and lime. International Journal of Sustainable Development & World Ecology 2008;15: S51–S55 Zhao J, Liu HP and Dong RC. Sustainable urban development: Policy framework for sustainable consumption and production. International Journal of Sustainable Development & World Ecology 2008;15: 317–324


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